Address for correspondence: Barbara K. Dunn, M.D., Ph.D., Basic Prevention Science Research Group, Division of Cancer Prevention, National Cancer Institute, National Institutes of Health, EPN 2056, 6130 Executive Boulevard, Rockville, MD 20852. Voice: 301-496-8541; fax: 301-480-4110.
bd62y{at}nih.gov
Selective estrogen receptor modulators (SERMs) are drugs that
bind to the estrogen receptor (ER); in some tissues they act
like estrogen (agonists), while in other tissues they oppose
the action of estrogen (antagonists). The SERM tamoxifen acts
as an estrogen antagonist in the breast in that it prevents
and treats breast cancer, but it acts as an estrogen agonist
in the endometrium, where it can induce cancer. Estrogen, and
to a lesser extent SERMs, are effective in preventing and treating
osteoporosis. Contrary to the prevalent hypothesis that estrogen
provides benefit to women with regard to secondary prevention
of coronary heart disease (CHD), randomized clinical trials
have demonstrated that estrogen is associated with an increased
risk of CHD in this population of women. Conflicting results
have been reported on the effect of estrogens on cognitive function.
The latest and largest randomized clinical trials have demonstrated
a beneficial role in short-term memory in nondemented women,
in contrast to the absence of such benefit in improving symptoms
in women with Alzheimer's disease. Although estrogens have been
used successfully to treat some menopausal symptoms such as
hot flashes, the SERMs tamoxifen and raloxifene actually induce
or increase hot flashes. Data on the beneficial and adverse
effects of estrogen and SERMs are reported along with an elaboration
of the constellation of properties that would characterize an
ideal SERM working through the ER.
